Datasheet LTZ1000, LTZ1000A (Analog Devices) - 5

LTZ1000/LTZ1000A
applicaTions inForMaTion Setting Control Temperature
is because normal operating power dissipation in the The emitter-base voltage of the control transistor sets the LTZ1000A causes a temperature rise of about 10°C. Of stabilization temperature for the LTZ1000. With the values course both types of devices should be insulated from given in the applications, temperature is normally 60°C. ambient. Several minutes of warm-up is usual. This provides 15°C of margin above a maximum ambient For applications not requiring the extreme precision or of 45°C, for example. Production variations in emitter-base the low noise of the LTZ1000, Linear Technology makes a voltage will typically cause about ±10°C variation. Since broad line of voltage references. Devices like the LT1021 the emitter-base voltage changes about 2mV/°C and is can provide drifts as low as 2ppm/°C and devices such as very predictable, other temperatures are easily set. the LM399A can provide drifts of 1ppm/°C. Only applica- Because higher temperatures accelerate aging and decrease tions requiring the very low noise or low drift with time of long-term stability, the lowest temperature consistent with the LTZ1000 should use this device. See Application Notes the operating environment should be used. The LTZ1000A AN-82 and AN-86 for further information. Consult the Linear should be set about 10°C higher than the LTZ1000. This Technology Applications department for additional help.
Typical applicaTions Negative Voltage Reference
ZENER + SENSE V+ 15V GND 0.1µF R4 R3 R2 13k 70k 70k 2 + 5 8 5 3 1k 7 2N3904 LT1013 10k – 6 6 4 1M 7 2 1 – 8 1 1N4148 0.1µF LT1013 3 + 4 400k* 1N4148 R5 R1 1k 120 0.022µF ZENER – FORCE ZENER – SENSE *PROVIDES TEMPERATURE COMPENSATION, DELETE FOR LTZ1000A V– ≥ 10V APPROXIMATE CHANGE IN REFERENCE VOLTAGE FOR A 100ppm CHANGE IN RESISTOR VALUES: 100ppm = ∆R(Ω) ∆VZ R1 0.012Ω 1ppm R2 7Ω 0.3ppm R3 7Ω 0.2ppm R4/R5 RATIO ∆R = 0.01% 1ppm BOTH A1 AND A2 CONTRIBUTE LESS THAN 2µV OF OUTPUT DRIFT OVER A 50°C RANGE 1000 TA02 1000afe For more information www.linear.com/LTZ1000 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Revision History Package Description Related Parts